Advice on work problem, please help!?

Do not make "her" problem your problem! You said that she has issues missing work and losing things so you do not need to defend her. If asked just be truthful, if you have not witnessed any problems say so ,but if you have, you don't need to embellish on them. It is not up to you to decide if she is being treated unfairly and it is not your job to monitor her behavior. Just do you job and take care of your own business. Good luck